A widely used form of clutch release mechanism employs a clutch release fork pivotally mounted in the housing enclosing the clutch assembly of a vehicle and connected to the clutch pedal in the passenger's compartment of the vehicle by a cable. The release lever actuates a release bearing which acts directly on inwardly extending fingers of a diaphragm spring or on clutch release levers in a coil spring clutch. The clutch release mechanism maintains a light pressure on the release bearing when the clutch is engaged so that the bearing is in constant engagement with the diaphragm spring fingers or the clutch release levers.
During use of the vehicle over an extended period of time, the friction surfaces of the clutch disc will gradually wear so that the clutch pressure plate must travel farther toward the flywheel to fully engage the clutch. In turn, the spring fingers or release levers urge the release bearing farther away from the clutch disc and causes the cable to urge the clutch pedal to a more extended position. Various self-adjusting mechanisms have been proposed to compensate for clutch lining wear, but their construction and/or effectiveness have not been satisfactory. The present invention obviates these problems in providing a simplified and effective automatic adjustment mechanism.